Bone surgery operations that involve cutting of the bony tissue (osteotomy) and/or modeling thereof (osteoplasty) have hitherto been performed with manual and/or rotary instruments. Manual instruments consist of scalpels and/or chisels operated by hand or with a mallet. Rotary instruments consist of motor-driven milling cutters or disks.
These methods both have serious limitations if they have to be used in difficult situations such as restricted surgical access, anatomically difficult bone conditions and particularly when it is necessary to operate in the vicinity of soft tissue.
The cutting characteristics of the techniques currently in use are unsatisfactory for the following reasons:                the cutting depth is poorly controlled;        the mechanical force is often excessive, therefore cutting directionality is lost and/or accidental fractures are caused; and        cutting is not selective and can therefore damage the soft tissue (for example the vascular nerve bundles).        